A conference system is used, for example, in an assembly or other conference, etc., attended by a large number of participants. The conference system is configured, for example, of a single control unit, a plurality of discussion units, connected via a communication line (wired or wireless) to the control unit, and microphones mounted on the discussion units.
The control unit controls operations of each discussion unit and controls operations of the entire conference system. The discussion unit collects the voice of a user of the discussion unit to generate audio information and transmits the audio information to the control unit.
The discussion unit is assigned to each participant of a conference. That is, in a large-scale conference with many participants, a large-scale conference system, with, for example, several hundred discussion units being connected, is used.
With such a large-scale conference system, the number of discussion units enabling speech at the same time is restricted, for example, to ten units, etc., for smooth progress of the conference and reduction of processing load of the system. On the other hand, a priority right (referred to hereinafter as “priority”) that always enables speech, etc., is set for a discussion unit used by a chairman, etc., of the conference for whom a restriction in speech should not be applied.
With a discussion unit for which the priority is not set, a speech request is made to the control unit to transition to a speech-enabled state. The speech request is made using so-called VOX (automatic voice recognition) or a depression operation of a button as a trigger. The speech request is permitted or rejected, for example, by the chairman, etc.
Conference systems, with which a speech request is made using VOX or button depression as trigger, have been proposed thus far.